/**
 * Created by liting on 2015/12/8.
 */
function createCode(paDivId) {
    this.code = "";
    this.codeLength = 6; //验证码的长度
    this.checkCode = document.getElementById(paDivId);
    var codeChars = new Array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'); //所有候选组成验证码的字符，当然也可以用中文的
    this.create = function () {
        this.code = "";
        for (var i = 0; i < this.codeLength; i++) {
            var charNum = Math.floor(Math.random() * 52);
            this.code += codeChars[charNum];
        }
        if (this.checkCode) {
            this.checkCode.className = "code";
            this.checkCode.innerHTML = this.code;
        }
    }
}